0
Research Papers: Flows in Complex Systems

Integrated Motor/Propulsor Duct Optimization for Increased Vehicle and Propulsor Performance

[+] Author and Article Information
Stephen A. Huyer1

 Naval Undersea Warfare Center, Newport, Rhode Island 02841stephen.huyer@navy.mil

Amanda Dropkin

 Naval Undersea Warfare Center, Newport, Rhode Island 02841

1

Corresponding author.

J. Fluids Eng 133(4), 041102 (May 12, 2011) (10 pages) doi:10.1115/1.4004006 History: Received September 23, 2010; Revised March 29, 2011; Published May 12, 2011; Online May 12, 2011

This paper presents a computational study to better understand the underlying fluid dynamics associated with various duct shapes and the resultant impact on both total vehicle drag and propulsor efficiency. A post-swirl propulsor configuration (downstream stator blade row) was selected with rotor and stator blade number kept constant. A generic undersea vehicle hull shape was chosen and the maximum shroud radius was required to lie within this body radius. A cylindrical rim-driven electric motor capable of generating a specific horsepower to achieve the design operational velocity required a set volume that established a design constraint limiting the shape of the duct. Individual duct shapes were designed to produce constant flow acceleration from upstream of the rotor blade row to downstream of the stator blade row. Ducts producing accelerating and decelerating flow were systematically examined. The axisymmetric Reynolds Averaged Navier–Stokes (RANS) version of fluent ® was used to study the fluid dynamics associated with a range of accelerated and decelerated duct flow cases as well as provide the base total vehicle drag. For each given duct shape, the propeller blade design code, PBD 14.3, was used to generate an optimized rotor and stator. To provide fair comparisons, the maximum rotor radius was held constant with similar circulation distributions intended to generate equivalent amounts of thrust. Computations predicted that minimum vehicle drag was produced with a duct that produced zero mean flow acceleration. Ducted designs generating accelerating or decelerating flow increased drag. However, propulsive efficiency based exclusively on blade thrust and torque was significantly increased for accelerating flow through the duct and reduced for decelerating flow cases. Full 3D RANS flow simulations were then conducted for select test cases to quantify the specific blade, hull, and shroud forces and highlight the increased component drag produced by an operational propulsor, which reduced overall propulsive efficiency. From these results, a final optimized design was proposed.

Copyright © 2011 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Typical Axisymmetric 2D fluent ® mesh generated using gambit ® highlighting the mesh in the duct region

Grahic Jump Location
Figure 2

Typical 3D fluent ® mesh generated using gambit ® highlighting the periodic meshes for the rotor and stator as well as the hull, duct and blade geometries

Grahic Jump Location
Figure 3

Vortex lattice solution of a rotor using PBD 14.3

Grahic Jump Location
Figure 4

Duct geometries for decelerating and accelerating ducts from dV =− 0.2–0.3

Grahic Jump Location
Figure 5

Baseline duct geometry and axial flow velocity contours

Grahic Jump Location
Figure 6

Axial velocity contours for six duct designs examined

Grahic Jump Location
Figure 7

Axial and radial velocity profiles taken at the rotor leading edge station for the full range of duct designs examined

Grahic Jump Location
Figure 8

Axial and radial velocity profiles taken at the stator leading edge station for the full range of duct designs examined

Grahic Jump Location
Figure 9

Axial and radial velocity profiles taken at the mid-duct centerline, 0.2*Rrotor normal to the hull surface from upstream of the rotor LE to downstream of the stator TE

Grahic Jump Location
Figure 10

Velocity magnitude gradient taken at the mid-duct centerline, 0.2*Rrotor normal to the hull surface from upstream of the rotor LE to downstream of the stator TE

Grahic Jump Location
Figure 11

Hull and shroud surface pressure distributions plotted along the x-coordinate relative to the rotor leading edge

Grahic Jump Location
Figure 12

Nondimensional mass flow rate for the accelerating and decelerating ducts examined

Grahic Jump Location
Figure 13

Rotor blade geometries for the dV = 0.2 duct configuration with taper ratios, τ, of 1.0, 0.8, 0.6, and 0.4

Grahic Jump Location
Figure 14

Optimized rotor propulsive efficiency for the range of duct accelerations examined

Grahic Jump Location
Figure 15

Hull and shroud drag with and without an operational rotor, scaled by the design thrust

Grahic Jump Location
Figure 16

Induced hull and shroud drag and induced total drag with and without an operational rotor and rotor and stator combination, scaled by the design thrust

Grahic Jump Location
Figure 17

Incipient cavitation velocity versus depth for a range of cavitation numbers

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In